It has been known to provide portable data storage modules such as credit cards. In general, these modules contain data storage means, such as random access memory, and memory supporting circuits. These modules may also contain a central processing unit (CPU) which is operable for storing data within the memory and for performing other functions, such as accounting related functions. Many of these data storage modules also contain a battery to provide operating power for the circuits contained therein. It has also been known to provide regulated DC power through electrical contacts exposed upon a surface of the module.
As can be appreciated, there are a number of disadvantages inherent in the use of such power coupling techniques. For example, if a battery is to power all of the circuits within the module for an extended period of time the storage capacity and, hence, the physical size of the battery may need to be excessively large.
For those modules that have terminals for the coupling of regulated DC power a plurality of such terminals may be required if the module requires for operation several different DC voltages. Furthermore, inasmuch as the power terminals may be directly coupled to integrated circuits within the module the terminals may conduct static electric discharges into the module and directly into the circuits. Such static electric discharges may degrade or cause the complete failure of the circuits. Also, during coupling of the module to the power terminals the circuit ground or common connection may be made after the DC power connection, resulting in possible damage to the circuits.
It is therefore one objective of the present invention to provide a magnetic power coupling means for coupling operating power into the cartridge.
It is a further objective of the present invention to provide for the coupling of operating power into the cartridge by means of two conductors from which a plurality of operating voltage levels may be derived.
It is a still further objective of the present invention to provide for the coupling of operating power into the cartridge that avoids the possibility of damage to cartridge circuits resulting from static electrical discharge on improper power sequencing.
It is one further objective of the present invention to provide a means for indicating the coupling state of a vault cartridge relative to a vault receptacle.